This invention relates to fluid conducting couplings and more particularly, but not by way of limitation, relates to fluid conducting couplings provided with a safely locking structure to prevent inadvertent, untimely decoupling.
Apparatus and method for coupling conduits, such as piping, tubing, and hosing, are known. For example, U.S. Pat. No. 4,222,593 (Lauffenburger) discloses a fluid conveying coupling having male and female coupling members, at least one (1) coupling lever pivotably mounted on the female coupling member and having a cam portion engageable in a groove in the male coupling member for releasably coupling the male and female coupling members together, and at least one (1) safety locking device for locking the coupling lever against accidental displacement from its coupling position. The coupling lever or arm 16, 18 is releasably locked in its latching position by locking pin 56 which is mounted for rectilinear movement along a path extending transversely to and overlying the coupling lever's longitudinal axis. A thumb lever 58 is pivotably mounted on the coupling body 14 to provide for pivotal displacement of thumb lever 58 about an axis extending parallel to the coupling's longitudinal axis. The longitudinal axis of lock pin 56 and the straight line path of movement of lock pin 56 lie in a plane normally intersecting the pivot axis of thumb lever 58 and the longitudinal coupling axis. Shortcomings of the Lauffenburger device include the mounting of the thumb lever and lock pin support structure on the body of the coupling member 14; and the perpendicular orientation of the thumb lever 56 to the coupling lever 16, 18, which requires the thumb lever 56 to extend around the body 14 creating the need for guard protectors 62, 63, and which apparently positions the thumb lever 58 such that two (2) human hands are required to operate the thumb lever while decoupling the coupling. Another shortcoming of Lauffenburger is the need for base 50 which seats against a surface of the female coupling member 14 and which must be fixed to the female coupling member 14 by welding or by screws, as illustrated in FIGS. 4 and 5 of Lauffenburger.
U.S. Pat. No. 4,295,670 (Goodall) discloses a quick disconnect cam locking safety coupling which uses locking levers 34 having openings 35 which receive a lug 36. The lug 36 is an integral part of socket 12, and therefore must be formed with the sock 12 or welded, screwed, or otherwise fastened thereto. Lug 36 has an opening 38 which receives a straight portion 42 of a wire locking pin 40 in order to hold the lever 34 in the coupled or locked position. Shortcomings of Goodall include the necessity of forming or mounting the lug 36 on socket 12, the use of a separate locking pin 78 (i.e. the latching device is not self-contained), and the need for two (2) human hands to lock and unlock the lever 34.
U.S. Pat. No. 4,647,075 (Vargo) discloses a quick disconnect coupling having a spring safety interlock. A wire safety spring element 46, 48 has a blocking loop 52 carried at the free upper end thereof and which lies across or projects into the path of latching handle 38, 40 in order to arrest unintentional decoupling of the latching handles 38, 40. The resilient nature of the wire safety spring 46, 48 creates a shortcoming in that it inherently weakens the blocking force of the spring safety interlock and renders it somewhat unpredictable.
There is a need for a fluid conducting coupling having a latching mechanism which is retrofittable to a standard cam and groove coupling or the like; which is wholly located on the coupling arm and not on the body of the coupling; which is self-contained and does not require separate pins, rings, or the like; which is retrofittable,e on materials other than aluminum and stainless steel; which does not have parts which protrude out of the coupling and may cause damage to the coupling and/or accidental decoupling; and which is operable with one (1) human hand.